neighbor bin_size neighbor_freq
  • bin_size = non-negative real number

  • neighbor_freq = positive integer


neighbor 1. 100
neighbor 2. 200


This command sets parameters for updating the neighbor list. In CAC simulatoins, each atom in the atomistic domain and each integration point in the coarse-grained domain maintain neighbor lists. Note that the non-integration point interpolated atoms in the coarse-grained domain do not maintain neighbor lists because their force/energy etc. are not calculated.

bin_size, in Angstrom, sets the length of the bin, which adds to the cutoff distance r_\mathrm{c} of the interatomic potential. All atoms within r_\mathrm{c} + bin_size from an atom/integration point are the neighbors of this atom. Note that each edge length of the processor domain cannot be smaller than 2 \cdot (r_\mathrm{c} + bin_size).

neighbor_freq is the frequency with which a check of whether the neighbor list should be updated is conducted. The neighbor lists of all atoms/integration points are updated if, with respect to the nodal/atomic positions recorded at the last check, any node or atom has a displacement larger than half the bin_size.

The initial number of neighboring atoms per atom/integration point is set in the limit command.

neighbor_init.f90 and update_neighbor.f90


neighbor 1. 200